Jolt mechanism for molding machines



July 10, 1928.

W. H. NICHQLLS JOLT MECHANISM FOR momma MACHINES Filed June 10, 1926 r a 5 MW m M R 0 m m J. [Y us a U 1 1 l Patented July 10, 1928.

UNITED STATES wmnmnr HENRY NICHOLLS, or BROOKLYN, NEW YORK.

JOL'I. MECHANISM FOR MOLDING MACHINES.

Application filed June 1.0, 1926. Serial No. 114,993.

This invention relates to moldin machines of the type provided with a flui pressureoperated jolti'ng mechanism which jolts the mold flask to pack the sand therein closely around the pattern.

The main object of the invention is to 1mprove the jolt mechanism and render it very rapid and efiicient.

Other objects and advantages of the invention will appear hereinafter.

In the drawing the figure is a sectional view showing my improved jolt mechanism embodied in a molding machine.

The molding machine indicated in the drawing is of the typeshownin my Patent No. 1,472,807, dated November 6, 1923.

Referring to the various parts by numerals, 1 designates the base of the machine. The base isformed at its upper end with a relatively large vertical cylinder 2 which is open at its upper end and closed at its lower end by a horizontal wall 3. Formed integrally with the cylinder 2 and the base 1, are laterally extending horizontal arms 4 and The arm 4 carries an upstandingpost 6 which serves as a support for a pressure head, not shown in the present case. In the cylinder 2 is fitted a large squeeze piston 7 which is closed at its lower end and open at its upper end. The upward movement of the squeeze piston is limited by a headed bolt 8 which is rigidly mounted in the bottom wall 3 of the cylinder and extends through an aperture in the bottom wall of the piston. The squeeze iston is provided with a packing ring 9 near its lower end adapted to bear against the inner wall of the cylinder 2. A relatively small central, vertically arranged cylinder 10 is integrally formed at the center of the bottom wall of the squeeze piston 7 and extends the entire height of the piston. The upper end of the cylinder 10 is open and its lower end is closed by the bottom wall 11 of the large squeeze piston. A short distance above the bottom of this cylinder is formed an exhaust port 12, of liberal size, which places the lower portion of the cylinder 10 in communication with the interior of the larger, surrounding portion of the squeeze piston and thence with the atmosphere.

A hollow, cylindrical jolt plunger 13 is fitted into the cylinder 10. This plunger is vertically elongated, its length being greater than the height of the cylmder. Adjacent its lower end the plunger is formed with a cross wall 14, the cylindrical wall of the plunger extending below the said cross wall in the form of an annular skirt flange 15. Near its lower end this flange is provided with a packing ring 16 which bears against the inner surface of the cylinder 10. Formed integrally with the upper end of the jolt piston is a jolt and squeeze head 17. The under side of this head is adapted to rest upon the upper end of the squeeze piston. The head extends across the upper end of the hollow jolt piston and closes it except for a threaded central opening 18 which is closed by a threaded plug 19. The piston is formed adjacent its upper end with a charging port 20 of liberal size. A port 21, very much smaller than the ports 12 and 18 extends centrally through the cross wall 14 of the plunger. The plunger, with its end walls defines an air reservoir 22 which extends throughout the greater portion of the length of the plunger and therefore has considerable volume. This reservoir is closed except for the ports 20 and 21. The port 21 admits air from the reservoir into the expansion space at the lower end of the cylinder 10, below the plunger and said port will be referred to as the admission port. The cross wall 14 of the plunger, and the skirt/flange 15, form a piston head for the plunger.

A manually operable valve 23 is mounted upon the lateral arm 5. This valve is of the same form as that shown in my Patent No. 1,472,807 and it is thought to be unnecessary to show and describe it in detail in the .present case. A pipe 24 leads from the valve pressed air, not shown, and in one position of its handle it is adapted to admit air to the cylinder 2. In another position of the handle the valve exhausts air from the c linder 2. A flexible pipe 25 of liberal size leads from the valve to the charging port 20 of the plunger reservoir- In one position of the valve air is admitted'through the pipe 25 to charge the reservoir.

The jolt and squeeze head 17 is formed with laterally extending arms 26 which carry vertically extending tubular sockets 27 at their outer ends. Secured upon the head is a pattern plate supporting frame 28. Upon this frame is secured the pattern plate 29, over which is placed the mold flask 30. Surrounding the frame 28 is a substantially rectangular flask-supporting frame 31 upon which the marginal front and rear edges of the flask are adapted to rest. The frame 31 is provided at its corners with depending guide pins 32 which slidably lit in the sockets 27. The ends of the frame 31 are centrally provided with depending plunger rods 33 which are slidably fitted within sockets 34 carried by the arms 4 and 5. llitlnn the sockets the rods .33 are adapted to be engaged by lock-up means, not shown, to hold the frame 31 and the flask in an elevated position after the squeezing operation. The olt and squeeze head 17 is not locked up but is free to return after a squeezing operation and to carry the pattern plate down with it. The

patterns are thus drawn from the mold.

In the jolt operation, after the flask'has been placed in position over the pattern plate and tilled with sand, the valve 23 is manipulated to direct air under high pressure through the ups 25 and the charging port 20 into the plunger reservoir 22. From the reservoir the air passes through the admission port 21 into the cylinder space below the plunger. The plunger is forced upwardly a short distance, carrying with it the head 17, the frame 31, the pattern plate and the flask. A short upward movement of the plunger causes the flange 15 to-uncover the exhaust port 12 to vent the cylinder 10 to atmosphere and permit the plunger and the various parts which it supports to drop back until the head 17 strikes the upper end of the squeeze piston 7. Immediately after this the plunger is again elevated for another jolting operation. The jolt movements continue in rapid succession as long as the valve continues to admit air into the pipe 25. By the provision of the relatively large air reservoir 22 closely adjacent to the expansion space below the plunger, :1 very rapid jolt operation is eti'ectbelow the plunger with the that very little ed. It has been found desirable in practice to reduce the extent of the flask lift and to cause the jolts to occur with much greater frequency. The present arrangement accomplishes this. The volume of the space is small in comparison volume .of the reservoir 22 even in the elevated position of the plunger. It is obvious, therefore, thatin equalizing with the small expansion space the pressure in the reservoir is reduced only slightly. A large volume of air at high pressure is therefore constantly maintained, during the jolt operation, almost at the immediate point where it is needed. The admission port 21 is made much smaller than the exhaust port in order air shall be lost when the cylinder space below the plunger is vented to atmosphere.

When the flask has been jolted sulliciently the valve is operated to shut oil air froln the pipe 25. -When the air valve is closed to stop the jolting, the comparatively considerable amount of air under pressure in the upper inder to raise the )iston 7-. The piston 7 carries upwardly with it the plunger 13, the head 17, the flask supporting frame 31, the flask 30 and the pattern plate until the presser board 35 is forced against the pressure head to compress the sand about the patterns. The valve is then operated to exhaust air from the cylinder 2 and permit these various parts to descend. The flask supporting frame 31 and the flask, as previously described, descend only part of the way and remain locked up until manually released from the lock-up means, not shown. The head 17 and the pattern plate, however, settle to their normal positions along with the piston 7 and thereby draw the patterns from the mold. Between successive operations of the valve to effect the jolt, a large amount of air pressure will be retained in the reservoir 22. The jolt will therefore start very. quickly when the valve is opened.

It will be understood that the jolt mechanism described is capable of being used with forms of molding machines other than that shown. I therefore, do not wish to be limited to its combination with the present form of machine.

What I claim is:

1. In a molding machine, a jolting mechanisln, comprising a vertically disposed cylinder; :1 plunger in said cylinder; a mold flask support adapted to be raised and lowered by 21 comthe reciprocation of the plunger; pressed air reservoir located closely adjacent to the cylinder and provided with a charging port to receive air from a compressor; a constantly open admission port smaller than the charging port connecting the reservoir with 0 the cylinder below the plunger therein; an exhaust port larger than the admission port. leading from the cylinder adjacent the lower end thereof; and nu-ans to automatically close the. exhaust port when the plunger 5 moves (0 its lowermost position and automatically open it when the plunger rises to a certain point.

2. In a molding machine, a jolting mechanism eoml'n'ising a vertically disposed cylin- 12o der; a plunger in said cylinder; a mold flask support adapted to be raised and lowered by the reciprocation of the plunger; a com-' pressed air reservoir carried by the plunger and provided with a charging port to receive air from a compressor; an admission port leading from the reservoir to the cylinder below the plunger: an exhaust port leading from the cylinder adjacent the lower end thereof; the plunger being adapted to close 0 the exhaust port in its lowermost position and to open said port when it raises to a certain heig 1t.

3. In a molding machine, a jolting mechanism comprising a vertically disposed cylinder; a verticall elongated plunger in said cylinder forms to define a compressed air reservoir provided with a charging port to receive air from a compressor; a mold flask support adapted to be raised and lowered b the reciprocation of the plunger in the cy inder; a constantly open admission ort smaller than said charging port leading mm the said reservoir to the cylinder below the plunger; and an exhaust port larger than said admission port leading from the c linder at a point spaced above the bottom t ereof and being closed by the plunger in its lowermost position and opened when the plunger is raised, to limit the upward movement thereof, the space volume in the cylinder below the plunger being small in comparison with the volume of the reservoir in all positions of the plunger.

1. In a molding'machine the combination of a relatively large vertical squeeze cylinder; a squeeze piston in said cylinder; a smaller jolt cylinder carried by the squeeze piston; a vertically elongated jolt plunger extending within the jolt cylinder formed to define a compressed air reservoir provided with a charging port; a flask support adapted to be raised and lowered by the reciprocation of said pistons; a constantly open admission ort smaller than said charging port leading from the reservoir to the jolt cylinder below the jolt plunger; an exhaust port larger than said admission port leading from the cylinder at a point spaced above the bottom thereof, and being closed by the plunger in its lowermost position and opened when the plunger is raised to limit its upward movement, the space volume in the cylinder below the plunger being small in comparison with the reservoir volume in all positions of the plunger; a manually operable valve; a charging pipe leading from the valve to the charging port of the plunger reservoir; and a to the squeeze cylinder below the piston.

5. In a folding machine, a jolting mechanism com rising a vertically disposed cylinder; a p unger in said cylinder; a compressed air reservoir carried by said plunger and provided with a chargin port; means to support a flask to be jolted 5y the reciprocation of the plunger; a constantly open ad'- mission port smaller than the charging port connecting-the reservoir and the cylinder below the plunger; and an exhaust ort larger than the admission port leading rom the cylinder at a oint spaced above its lower end and being osed b the plunger in its lowermost position an opened when the plunger is raised to limit its upward move- 1pe leading from the valve ment, the space volume in the cylinder below the plunger being small in comparison with the volume of the reservoir in all positions of the plunger.

6. In a molding machine, a jolting mechanism comprising a vertically disposed cylinder; a plunger in said cylinder a mold flask support adapted to be raised and lowered by the reciprocation of the lunger; a compressed air reservoir earrie by the plunger and provided with a charging port; an ad mission port leading from'the reservoir to the cylinder below the plunger; an exhaust port leading from the cylinder, the space volume in the cylinder below the plunger, in all positions of the plun er, being small in comparison with the v0 ume of the reservoir; and means to automatically close said exhaust port when the plunger approaches. its lowermost position and to automatically open said port when the plunger rises to a certain point.

7. A molding machine cushioning means, comprising a support, a cylinder member carried thereby, a piston member within thecylinder mem er and having a bore and a medial partition dividing the bore into two compartments, and controllable means for supplying ressure fluid to the cylinder, said partition aving a comparatively small opening to restrict the flow of fluid from one compartment to the other to provide a surplus amount of pressure fluid for automatically cushioningfithe last reciprocation of the piston mem r when the pressure fluid controllable means is closed.

8. A molding machine cushioning means, comprising a support, a cylinder member *carried thereby, a piston member reciprocably positioned within the cylinder member and having a jolt table at its upper end, a valve controlling the flow of expansion fluid to the cylinder, and an expansive fluid chamber in communication with and interposed between the valve and the cylinder to hold a sufiicient supply of expansive fluid after the valve is closed to cushion the last downward reciprocation of the piston.

9. A molding machine cushioning means, comprising a support, a vertical cylinder member carried thereby, a piston member reciprocably ositioned within the cylinder member an having means for holding a mold at its upper end, a manually operable valve controlling the flow of expansive fluid to the cylinder, and a chamber in communication with and interposed between the valve and the cylinder and bein of a size to hold sufficient expansive fluif after the closure of the valve to cushion the last downward reciprocation of the piston.

In testimony whereof I -hereunto aflix my signature.

WILLIAM HENRY NICHOLLS. 

